Crate linked_hash_table 

LinkedHashMap

A hash map that maintains insertion order and supports efficient O(1) push/pop from both the front and the back, similar to VecDeque.

Design

Each key-value pair lives in a heap-allocated node. The nodes form a doubly-linked list that tracks insertion order. A HashMap<K, NonNull<Node<K, V>>> gives O(1) lookup by key. Because all node pointers are owned by the map and the HashMap only stores raw pointers (never moves the pointed-to memory), pointer stability is guaranteed as long as the map is alive and the entry is not removed.

 head ⟷ node_A ⟷ node_B ⟷ node_C ⟷ tail   (sentinel nodes)
           ↑           ↑           ↑
       HashMap entries (key -> *mut Node)

The head and tail fields are sentinel nodes that never hold real data. Their key / value are never read; they merely anchor the list so that every “real” node always has both a prev and a next, eliminating many Option branches in the hot path.

Ordering contract

LinkedHashMap::insert_back and LinkedHashMap::insert_front preserve the position of an existing key: only the value is updated in-place. Use LinkedHashMap::move_to_back / LinkedHashMap::move_to_front to explicitly reorder an entry.

Re-exports

pub use iter::Drain;

pub use iter::IntoIter;

pub use iter::Iter;

pub use iter::IterMut;

pub use iter::Keys;

pub use iter::Values;

pub use iter::ValuesMut;

Modules

iter

Iterator types produced by LinkedHashMap.

Structs

LinkedHashMap

A hash map that preserves insertion order and exposes a [VecDeque]-like API with [insert_back], [insert_front], [pop_front], [pop_back], [front], and [back].

LinkedHashSet

A hash set that preserves insertion order and exposes a VecDeque-like API with insert_back, insert_front, [pop_front], and [pop_back].

OccupiedEntry

A view into an occupied entry in a LinkedHashMap.

SetDrain

Draining iterator - removes and yields every element in insertion order, leaving the set empty.

SetIntoIter

Consuming iterator - yields every element in insertion order.

SetIter

Iterator over &T elements in insertion order.

VacantEntry

A view into a vacant entry in a LinkedHashMap.

Enums

Entry

A view into a single entry in a map, similar to std::collections::hash_map::Entry.